he is former president bill clinton. he is hoping to pack enough political punch to topple a lot of targets. here is abc's jeff zeleny. >> reporter: bill clinton is back. >> look, i love kentucky, you've been good to me. >> reporter: plunging into one of the biggest battles of the year. the effort to knock off the top republican in the senate, mitch mcconnell. clinton said he turned gridlock into an art form. >> when there's a problem, do everything you can to make sure the problem is never fixed. it may work in an election year. get everybody upset and mad all the time but it is a dumb way to run a country. >> reporter: clinton helping mcconnell's opponent. secretary of state allison lunder again grimes. she was a teenager when she was president. here she is only 14 presenting roses to the clintons at their inauguration in 1993. surrounded by senators in washington, mcconnell brushed off clinton's visit. >> every time he comes, it is good for me. >> reporter: perhaps but clinton is the biggest draw. fueled by nostalgia